Japanese company Yamaha, meanwhile, has produced 95-kilogram (209-pound) robot helicopter that is 3.6 metres (11.8 feet) long and has a 256 cc engine.
It flies close to the ground at about 20 kilometres per hour (12 miles per hour), nothing but an incredible stroke of luck could stop it if it suddenly appeared in the sky above the White House -- and it is already on the market.
Bruce Simpson, an engineer from New Zealand, managed to produce an even more dangerous contraption in his own garage: a mini-cruise missile. He made it out of readily available materials at a cost of less than 5,000 dollars (4,000 euros).
What a great idea, killer robot helicopters. Thanks, Yamaha! I can't wait to run screaming from one as it lasers my limbs off, or whatever.